Alan Stripp

Alan Stripp, who died on February 18 aged 84, turned his experience as a
wartime codebreaker to good effect in both historical and fictional accounts
of the secret war against the Japanese.

7:22PM GMT 10 Mar 2009

In Codebreaker in the Far East (1989), Stripp described his career as a cryptanalyst within an account of the contribution of British signals intelligence in the Allied victory in Burma in 1945. More tantalisingly, in 2001, he published The Code Snatch, a fictionalised account of the theft of a Japanese military codebook in late 1944. The novel was based on true events, though Stripp would never be drawn on the exact points where fact and fiction coincided.

Alan Stripp with an Enigma machine in 1993

Stripp's career in Signals Intelligence began in 1943 when, as a first-year Classics scholar at Trinity College, Cambridge, he received a note from his tutor saying that an Army officer was coming to interview people about "something to do with languages". To Stripp's surprise his interviewer seemed more interested in his proficiency in crosswords and his ability to read an orchestral score than "grit, gristle and leadership", so that at one point he wondered whether he was being conscripted for a military band. Things became only slightly clearer two months later when he was dispatched to Bedford with around 35 other recruits, mostly Oxbridge classicists, to take a crash course in written Japanese.

The course was devised and run by Oswald Tuck, a retired naval captain who had taught himself Japanese while serving on the China station before the First World War. When the Japanese invaded Burma in January 1942 the School of Oriental and African Studies, then the only British institution teaching the language, insisted that it would be impossible to master in less than two to three years. Tuck claimed he could teach it in six months. After only five months he was able, in the summer of 1942, to send some of his students to the Government Code and Cipher School at Bletchley Park.

Stripp arrived at Bletchley Park in the spring of 1944 and was set to work translating signals decoded via the Japanese Air Force code known as 6633, which had been broken before his arrival. Most came from Burma, and Stripp was "staggered" by the amount of useful information they contained. Even though the war was thousands of miles away, he became so involved that "it was almost a shock to leave the building at the end of a long shift and emerge into the humdrum Midland landscape with not an oriental face in sight".

Code 6633 would prove particularly important during the later stages of the campaign in Burma. In late 1944 codebreakers detected the pulling back of one of the Japanese air regiments, a crucial early hint that Japanese plans had changed and that they intended to fight from behind the Irrawaddy and not in front of it. This titbit of information influenced General Slim into replacing plans for a decisive battle on the plain in front of the river with a plan to strike at the nerve centre of Japanese operations at Meiktila to the south, a change of strategy that effectively won him the campaign.

In the summer of 1944 Stripp was posted to the Wireless Experimental Centre at Delhi. The tide had turned against the Japanese by this time, though signals intelligence continued to play a vital role. In his novel, Stripp told the story of how, when it was learned from an intercept that the Japanese planned to change code "2244" for a new one, the Allies conceived a plan to snatch the only two volumes of the new codebook in existence. While codebreakers were confident they would break the new code, the time needed would destroy the British Army's momentum and give Japanese forces time to recover.

The plan involved sending a bogus radio signal to a Japanese intelligence officer in Rangoon, pledging him to secrecy and ordering him to hand the two volumes over to a "Japanese general" who would shortly be arriving by plane at Mingaladon airbase. The plane, according to Stripp's story, was a captured Japanese aircraft and the "general" an Allied officer of Japanese parentage.

In his earlier book Stripp recorded that "in late 1944 there were hints of the impending introduction of a new codebook. Fortunately this did not happen." Later he admitted to his wife that the episode had involved him being flown behind Japanese lines in Burma. It is probable that the full story will never be told, for when hostilities came to an end, intelligence units in the Far East were ordered to burn their records. Stripp himself recalled "coolly" presiding as "whole truckloads of paper" were shovelled into "a poorly designed and hastily built incinerator, from the chimney of which, as we watched, Top Secret documents wafted, half burned, over the astonished western suburbs of New Delhi."

The son of a mathematics teacher and crossword compiler, Alan Stripp was born on October 17 1924.

After the war in Burma came to an end in 1945 he was posted to a listening post near Rawalpindi on the North West Frontier, where he took a crash course in Farsi to monitor radio traffic during a build-up of tension between Iran and the Soviet Union over competing claims in Azerbaijan. Later he was assigned to decode Afghan signals concerning guerrilla activity by the Faqir of Ipi.

On being demobbed in 1946 Stripp returned to Cambridge but changed his course from Classics to Japanese, with Classical Chinese and Far Eastern History. After graduation he worked for 10 years for the British Council in Portugal and Indonesia, before becoming an administrator for Cambridge University's Board of Extra Mural Studies, also lecturing on music.

With his wife Mary, whom he married in 1949, he helped to organise a music festival at Linton, the Cambridgeshire village where they lived, and founded the Phoenix String Orchestra which gave 130 concerts before it disbanded in 1980. In later life he was director of the Cambridge University Summer Schools on the British secret services.

In his preface to Codebreaker in the Far East Stripp explained that he had decided to publish to avoid being caught by sections of the impending Official Secrets Act. He went on to co-edit, with Sir Harry Hinsley, Codebreakers: The Inside Story of Bletchley Park (1993), a book which was only possible because he and others had been released from their oaths of official secrecy.